The present invention concerns fire suppressant additive compositions for polyurethane unitary backing systems for carpets and the like and to such unitary backing systems containing such additive composition as well as to substrates backed therewith.
The polyurethane unitary backing systems currently employed in the carpet industry generally possess adequate dimensional stability, bundle wrap, tuft lock and pilling and fuzzing characteristics. However, these systems do not possess adequate fire suppressant characteristics which are required in flame specification for Airlines in Federal Aviation Regulation (FAR), Part 25, Section 25.853b (Airworthiness Standards) with the currently employed suppressant additives such as calcium carbonate, iron compounds and alumina trihydrate. For these applications, passing of a vertical flammability test at a minimum of 1550.degree. F. by FSTM Standard 191, Method 5903.2 employing type B gas is required.
The present invention provides a synergistic fire suppressant additive system for use in polyurethane unitary backing systems which will pass the aforementioned vertical flammability test at 1550.degree. F. and, in many instances, will pass this test at even higher temperatures.